''Beyrichites'' is an extinct genus in the

ammonoid Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttlefish) ...

s cephalopod, order

Ceratitida Ceratitida is an order that contains almost all ammonoid cephalopod genera from the Triassic as well as ancestral forms from the Upper Permian, the exception being the phylloceratids which gave rise to the great diversity of post Triassic ammoni ...

from the Lower and Middle Triassic of southern Europe, Asia, and western North America. ''Beyrichites'' has an involute, discoidal shell with a narrowly arched venter and sigmoidal ribbing that tends to disappear on the outer whorl. The suture is subammonitic, meaning the saddles are serrate as well as the lobes. Two subgenera are recognized: ''B. (Beyrichites)'' from the Lower and Middle Triassic, which has no tubercles, and ''B. (Gangadharites)'' from the Middle Triassic of the Himalaya which has tubercles on the whorl sides.

References

Treatise on Invertebrate Paleontology The ''Treatise on Invertebrate Paleontology'' (or ''TIP'') published by the Geological Society of America and the University of Kansas Press, is a definitive multi-authored work of some 50 volumes, written by more than 300 paleontologists, and co ...

, Part L; Ch. Mesozoic Ammonoidea. Geological Soc of America and U Kansas Press, R.C Moore (ed) Ceratitoidea Triassic ammonites of North America Ceratitida genera Ammonites of Europe Middle Triassic life {{Ceratitida-stub